The Scientific Core exists to facilitate the scientific projects within the program. The services, materials and reagents provided by the Scientific Core are purified scrapie prions, PrP antibodies, synthetic peptides and oligonucleotides, recombinant PrP variants, transgenic mouse screening and a chemical and biochemical analytical service. This core will be directed by Dr. Michael Baldwin, an analytical chemist of considerable experience who directed a core service laboratory in the University of London for 14 years and who has devoted himself for the last six years to reach into the chemistry and biochemistry of the prion protein. The preparation of purified prions has been carried out in this laboratory for more than a decade. In recent years this program has been supervised by Ms. Hana Serban. She will supervise the production of PrP antibodies, crucial to the success of projects 1-4 and Core C. Two SRA's, both having considerable experience, will synthesize peptides and oligonucleotides. Peptides are required for projects 3-5, and for antibody production. oligonucleotides will be needed for projects 3 and 4 and this core for transgenic mouse production and for screening these mice as well as providing a variety of other tools for molecular biology. Recombinant PrP variants will be expressed in culture by Dr. Michael Scott, an outstanding molecular biologist, for use in projects 4 and 5. The screening of transgenic mice which is essential for project 3 will be carried by Ms. Ruth Koehler. An SRA will carry out chemical and biochemical analysis, which will play an important role in antibody production and transgenic mouse production and will also benefit projects 2-5. All of these activities are currently being carried out very successfully in this laboratory and there are highly experienced personnel already in post.